Trends in case-fatality of stroke in Finland during 1983 to 1992.

BACKGROUND AND PURPOSE: Stroke mortality has been declining in Finland during the past 20 years. It is not known, however, whether this favorable development is attributable to the decline in the incidence or case-fatality of stroke. For this reason we examined the trends in case-fatality of stroke, including trends by subtype of stroke. METHODS: The analyses were carried out using data of the community-based FINMONICA Stroke Register, which was operating in three geographic areas of Finland during 1983 to 1992. All stroke events (n = 11,171) in persons aged 35 to 74 years were included in this register. RESULTS: The 28-day case-fatality of stroke fell yearly by 3.6% (P = .01) in men and by 2.6% (P = .2) in women. At the end of the study period, the average 28-day case-fatality of all strokes was 20% in men and 21% in women. Considerable differences by subtype of stroke were observed. The 28-day case-fatalities at the end of the study period were in men-56% for subarachnoid hemorrhage, 42% for intracerebral hemorrhage, and 14% for cerebral infarction. In women, the corresponding figures were 49%, 49%, and 14%. The 28-day case-fatality of subarachnoid hemorrhage did not change during the study period, but for intracerebral hemorrhage, a significant decline was observed in men and there was a declining trend also in women. The 28-day case-fatality of cerebral infarction declined significantly in both genders. CONCLUSIONS: With the exception of subarachnoid hemorrhage, the 28-day case-fatality of stroke has fallen in Finland. It is likely that this fall has contributed to the decline in stroke mortality.

Ten-year trends in stroke incidence and mortality in the FINMONICA Stroke Study.

BACKGROUND AND PURPOSE: The trends in stroke incidence reported so far have not been entirely consistent, although declining trends in mortality from stroke have been reported from a number of studies around the world. This study aims to evaluate the 10-year trends (from 1983 through 1992) in incidence, attack rate, and mortality of stroke in the Finnish population. METHODS: A population-based stroke register was set up in the early 1980s to collect data on all suspected events of acute stroke that occurred in the population aged 25 to 74 years permanently residing in three geographic areas of Finland: the provinces of Kuopio and North Karelia in eastern Finland and the Turku-Loimaa area in southwestern Finland. Trends in age-standardized attack rates, incidence, and mortality were calculated for the period studied. RESULTS: During the 10-year study period, 11 392 acute stroke events occurred in the monitored populations. A statistically significant decline was observed in the pooled FINMONICA data, both in the incidence of stroke (-1.7% with 95% confidence interval [CI], -3.0% to -0.5% per year in men; -2.2% with 95% CI, -3.6% to -0.7% per year in women) and in mortality from stroke (-5.2% with 95% CI, -8.2% to -2.2% per year; -4.7% with 95% CI, -8.2% to -1.2% per year). The attack rate of stroke also declined significantly in both sexes. When the areas were considered separately, the declining trends were observed within each area. The decline in incidence of stroke was, however, statistically significant only among men and women in Kuopio and among women in Turku/Loimaa. Mortality declined significantly in all three areas among men but among women only in Kuopio. The incidence to mortality rate ratio increased during the study period, indicating a steeper fall in mortality than in incidence. CONCLUSIONS: A substantial decline in both stroke incidence and mortality was observed in the adult and elderly population in the FINMONICA study areas. Part but not all of the decline in stroke mortality, observed also in the official mortality statistics, can be attributed to the decline in stroke incidence during this 10-year period.

Declining trends in incidence, case-fatality and mortality of stroke in three geographic areas of Finland during 1983-1989. Results from the FINMONICA stroke register.

Stroke mortality has decreased during the last decade in many industrialized countries, but there has been no clear evidence for a decline in the incidence of stroke. The present study analyzes the trends in the incidence, mortality and case-fatality of stroke in Finland from 1983 to 1989. We used data from the FINMONICA stroke register, a community based register collecting information on all suspected stroke cases aged 25-74 in three geographical areas of Finland. Annual attack rate, incidence, mortality and case-fatality rates were calculated for all strokes and for different subcategories of stroke. A linear regression model was applied to calculate the yearly trends of these rates. In men, the attack rate of stroke was 336/100,000 in 1983 and 310/100,000 in 1989 (-8% during the observation period); incidence declined from 269/100,000 in 1983 to 236/100,000 in 1989 (-12%); mortality declined from 82/100,000 to 64/100,000 (-22%), and case-fatality declined from 25% to 21% (-18%). Also among women similar declining trends were observed (-11%, -13%, -16%, and -10% respectively), but they were not statistically significant. In both incidence and mortality of stroke, the decline was seen in all age groups. Incidence and mortality of cerebral infarction declined similarly to all strokes. A large fall in the incidence (-24% in both men and women) and mortality (-38% in men and -27% in women) of subarachnoid haemorrhage was also observed. An increasing trend, although not significant, was instead observed for cerebral haemorrhage. First stroke and especially first cerebral infarction contributed most to the decline in case-fatality. The availability of computerized brain tomography improved from 18% in 1983 to 60% in 1989. We observed a fall in the incidence, mortality, and case-fatality of stroke during 1983-1989. Among the subtypes of stroke, cerebral infarction contributed most to the decline, but the data suggested also a declining trend in the incidence and mortality of subarachnoid haemorrhage, observed now for the first time in Finland since the 1960s. The fall in the incidence of stroke was not as steep during the 1980s as it was during the 1970s; Finland is anyhow the only European country which has reported a decreasing trend in stroke incidence during the 1980s. We need now to investigate how much the decline in the classical risk factors for stroke observed in Finland during the last two decades predicts the observed trends.

Stroke incidence and case fatality in Finland and in Akita, Japan: a comparative study.

The incidence and case fatality of stroke from 1983 to 1985 from the community-based stroke register of the FINMONICA study in Finland were compared with the corresponding rates in the hospital-based register of Akita in Japan collected during 1984-1986. The comparability of the two registers was assessed, and case fatality was compared only in hospitalized cases. In Akita, the age-standardized incidence of cerebral haemorrhage in people aged 25-74 was twice that in FINMONICA, while the reverse was true for incidence of cerebral infarction. Case fatality from stroke within 48 h of onset was higher in FINMONICA than in Akita in each stroke subtype. The incidence and mortality of subarachnoid haemorrhage were similar in the two populations. The differences in early case fatality are probably due to dissimilarities in the severity of the stroke attacks rather than discrepancies in early treatment. Coding practices and also a more unlikely selection bias due to the differential use of computerized brain tomography in the two countries may play a role in differences in incidence and case fatality between these two countries.

Stroke mortality and case-fatality rates in three geographic areas of Finland from 1983 to 1986.

BACKGROUND AND PURPOSE: Our aim was to describe the mortality and early case-fatality rates of stroke in three geographic areas of Finland during 1983 to 1986 by means of a community-based stroke register and to estimate the accuracy of registration of stroke deaths in the official statistics compared with the FINMONICA stroke register. METHODS: Annual and average mortality and case-fatality rates of stroke were derived from data collected in the FINMONICA stroke register during 1983 to 1986. Age-specific and age-standardized rates were calculated for the three areas, and the results were compared with the official mortality statistics and with the case-fatality figures published previously in the literature for Finland and elsewhere. RESULTS: Mortality from stroke in the three FINMONICA areas was between 73 and 90 per 100,000 per year among men aged 25 to 74 years and between 42 and 55 per 100,000 per year among women in the same age group. Average case-fatality was similar in the three areas and globally high: 20% to 27% in men and 24% to 28% in women. Approximately half of the fatal strokes occurred within less than 2 days from the onset of the attack, and a further 25% within the first week. Hemorrhagic strokes accounted for 54% to 81% of all fatal strokes occurring in less than 2 days among men, while among women the corresponding proportions varied in the three areas between 35% and 74%. Of cerebral infarctions, approximately 28% to 37% among men and 19% to 20% among women were fatal within less than 2 days. Although the number of fatal strokes was similar in both the FINMONICA register and official mortality statistics, only 82% to 85% of the stroke cases were common in both registers; a further 13% to 14% of the cases classified as stroke deaths in the FINMONICA register could also be found in the official mortality statistics, but the underlying cause of death was something other than stroke. CONCLUSIONS: The reliability of the Finnish official mortality statistics with regard to stroke deaths is reasonably good in aggregate numbers, but at the individual level considerable discrepancies seem to occur. Mortality from stroke in Finland has not declined further after 1979 and remains high internationally. Early case-fatality of stroke also seems higher in Finland than in most other countries. We believe that both the high incidence of stroke and the severity of the attacks are contributing to mortality and case-fatality rates of stroke in Finland.

The FINMONICA Stroke Register. Community-based stroke registration and analysis of stroke incidence in Finland, 1983-1985.

In the early 1980s, a standardized community-based stroke register was started in three geographic areas in Finland: North Karelia and Kuopio in eastern Finland and Turku/Loimaa in southwestern Finland. The results from the first 3 years, 1983-1985, confirmed the high incidence of stroke in Finland. The incidence of stroke was higher in eastern Finland than in the southwestern part of the country. The age-standardized annual incidence among men aged 25-74 years varied from 206 per 100,000 population in southwestern Finland to 322 per 100,000 population in the province of Kuopio in eastern Finland. Among women aged 25-74, incidence was 119 and 187 per 100,000 population in these two areas, respectively. The age-standardized male:female ratio in incidence was 1.7, slightly higher than that previously reported in Finland. Out of 3,574 stroke events registered, 78% were first events without a history of previous stroke. People aged 65-74 years accounted for 45% of all events among men and 62% of all events among women. The authors' experience shows that the geographic variation in stroke incidence and attack rates is difficult to assess even within a country with a relatively uniform health care system. Rigorous standardization and quality control is needed for the assessment of long-term trends; this is the primary goal of the FINMONICA Stroke Register. The findings of this study suggest that the incidence of stroke is still high in Finland, although mortality from stroke has steeply declined during the past 15-20 years. The number of stroke survivors in Finland may actually be increasing. Since the occurrence of stroke is high in Finland as compared with other countries, intensified primary and secondary prevention measures are needed to reduce it.

Epidemiology of subarachnoid hemorrhage in Finland from 1983 to 1985.

The age-standardized incidence of subarachnoid hemorrhage was 33/100,000/yr among Finnish men and 25/100,000/yr among Finnish women. Subarachnoid hemorrhage represented 11% of all strokes detected during 1983-1985 in the community-based stroke register in three areas of Finland. Age-standardized mortality from subarachnoid hemorrhage was 18/100,000/yr among men and 12/100,000/yr among women aged 25-74 years, representing in men 22% and in women 23% of all deaths from stroke in the register. The case-fatality rate of subarachnoid hemorrhage was high: 35% among men and 33% among women within 2 days after the onset of the stroke attack and 48% in men and 46% in women at 1 month. Our findings suggest that the incidence and mortality of subarachnoid hemorrhage in Finland are among the highest worldwide, although differences in criteria, study methods, and classification procedures reduce the comparability of studies from different countries. The occurrence of subarachnoid hemorrhage in our present study is also higher than that previously reported in this country. We believe that this is more likely due to changes in diagnostic classification and improvements in detection of the disease than to a real increase in the morbidity and mortality of subarachnoid hemorrhage.

Characterization of the perivascular reticulin network in a case of primary brain lymphoma. Immunohistochemical demonstration of collagen types I, III, IV, and V; laminin; and fibronectin.

The character of the silver positive reticulin network was analyzed with immunofluorescence and immunoperoxidase methods in an intra vitam diagnosed case of primary brain lymphoma. The network was shown to contain connective tissue proteins rich in hexose-sugars, such as type III collagen (classical "reticulin"), basal lamina constituents type IV collagen and laminin, pericellular type V collagen, as well as fibronectin (protein involved in cell adhesion). On the other hand, very little of the fibrous type I collagen was discernible. Similarly as the silver positive network, the immunohistochemically demonstrable reticulum seemed to hold the cells in the perivascular location, and once it was broken diffuse spread into the tissue occurred. Since malignant cells of B-lymphocyte origin are not known to synthesize so-called reticulin, it is suggested that the network in primary brain lymphomas is produced by cells in the brain parenchyma (possibly pericytes or astrocytes) as a protective attempt to restrict the spread of foreign cells into the brain.

Epilepsy as a sequel to cerebrovascular accident.

In 1973 345 patients were admitted to Turku City Hospital because of cerebrovascular accident, 21 of them having epilepsy as a sequel after an earlier stroke or developing epileptic seizures during an observation period of 4 years. In the same year 27 patients were admitted because of epilepsy, 11 of them showing onset of seizures after an earlier stroke. Thus 32 patients, or 9,0 per cent of 356 cases with CVD proved to have epilepsy. The incidence of epilepsy did not depend on the nature of the vascular lesion. In three quarters of the cases the onset occurred within two years after the initial stroke. Most patients had generalized seizures, quite a few only convulsions with focal origin or psychomotor attacks. EEGs showed features of epileptic nature in half of the cases, although mostly slight. The importance of diagnosing epilepsy after a cerebrovascular accident is emphasized because recurrences of seizures can be successfully prevented with anticonvulsant therapy. Deepening of the paralytic signs after seizure is often misdiagnosed as a relapse of the stroke itself.

On the occurrence and prognosis of aphasia in patients with cerebral infarction.

Of 338 consecutive patients with cerebral infarction, aphasia in the acute phase was found in 96. Of these, 18 had totally recovered from aphasic speech disturbances when leaving the hospital. The patients were examined 2-8, in average 6 years after the onset of the illness. 39% of them had died, 27% still suffered from aphasic speech disturbances, while 32% were recovered from aphasia. In addition, disturbances in writing, reading, and/or calculation were observed in more than the half of the survivors. Of patients over 65 years of age 56% were dead compared with 32% of younger patients. Aphasia was observed relatively more in geriatric patients, and the recovery of them was poorer.